基于块稀疏二维联合模型的双基地ISAR高分辨成像算法  

Bistatic ISAR High Resolution Imaging Algorithm Based on Block Sparse Two-dimensional Joint Model

作　　者：吴云军 黄国鹏 陈文峰[2] WU Yunjun;HUANG Guopeng;CHEN Wenfeng(The Second Military Representative Office of Rocket Force Equipment Department in Wuhan,Wuhan 430000,China;Air Force Early Warning Academy,Wuhan 430019,China)

机构地区：[1]火箭军装备部驻武汉地区第二军事代表室,湖北武汉430000 [2]空军预警学院,湖北武汉430019

出　　处：《数字制造科学》2022年第2期136-140,共5页

摘　　要：为利用目标的块稀疏特性,提高双基地ISAR在有限数据条件下的成像性能,提出基于块稀疏二维联合模型的双基地ISAR高分辨成像算法。首先分析了二维联合成像中块稀疏结构,实际的双基地ISAR图像通常具有块稀疏结构的特点,因此图像中的散射点通常呈现出聚集的块稀疏结构;其次在二维联合高分辨成像时充分利用这一先验信息,将块稀疏二维联合成像问题转换为重赋权l1最小化问题;然后利用重赋权l1最小化框架进行迭代求解,每次迭代中的加权l1最小化问题利用CAMP算法求解;最后利用向量化算子的性质导出了矩阵形式的迭代重赋权算法,由前一次稀疏解对应的系数及其附近的系数实现权值的更新,提高了成像性能。基于电磁计算的双基地ISAR成像数据验证了所提算法能够提高块稀疏目标的重构性能。To improve the imaging performance of Bistatic inverse synthetic aperture radar(ISAR)under limited data conditions,a Bistatic ISAR high-resolution imaging algorithm based on block sparse two-dimensional joint model is proposed in this paper.The actual Bistatic ISAR image usually has the characteristics of block sparse structure,so the scattering points in the image normally shows an aggregated block sparse structure.Firstly,the block sparse structure in two-dimensional joint imaging is analyzed.Secondly,making full use of this prior information in two-dimensional joint high-resolution imaging,the block sparse two-dimensional joint imaging problem is transformed into a re-weightedl1 minimization problem.Then,the weightedl1 minimization framework is used for iterative solution,and the weightedl1 minimization problem in each iteration is solved by complex approximate message passing(CAMP)algorithm.Finally,an iterative weighting algorithm in matrix form is derived by using the properties of vectorization operator.The weights are updated by the coefficients corresponding to the previous sparse solution and their nearby coefficients,which improves the imaging performance.Bistatic ISAR imaging data based on electromagnetic calculation verifies that the proposed algorithm can improve the reconstruction performance of block sparse targets.

关 键 词：块稀疏结构 二维联合模型 双基地逆合成孔径雷达 复数近似消息传递 

分 类 号：TN957.52[电子电信—信号与信息处理]